ABSTRACT

Combining multi-Parametric Sensitivity Analysis (MPSA) with stream transport
modeling is proposed to determine the relative importance of physical and biogeochemical
processes controlling natural attenuation of contaminants. The MPSA is based
on a large number of Monte-Carlo simulations to identify the sensitive parameters
over a broad range of each parameter. This combined approach is applied to the
transport of a mining contaminant, dissolved manganese in Pinal Creek basin,
Arizona. The MPSA results show that transport of dissolved Mn(II) in Pinal Creek
is controlled mainly by ground-water inflow, resulting spatial variation of
pH in stream water, and the effect of pH on microbially mediated Mn(II) oxidation
in the hyporheic zone.